It is commonly known that directional solidification can enhance the structural properties of a cast metal part. Accordingly, it is desirable to cool a mold from one or several distinct locations.
It is known in the prior art to cast metal within a pressure vessel. This method consists essentially of disposing a mold and a source of molten metal, within a mold. The vessel is then pressurized in a manner which forces the molten metal into the mold. Since the entire process takes place within a pressure vessel, the pressure differential between the inside of the mold and the outside of the mold can be controlled, thus allowing the use of thin walled molds. It was known in the past to effect directional solidification by thermally contacting the mold with a cooled member such as a chill plate. However, there is no apparatus or method disclosed in the prior art which uses the gas pressurization means to chill or directionally solidify a metal casting within a pressure vessel.